Due to the advantages of low production cost, simple structure, low power consumption, small size, and ease of assembly, the light emitting diode (LED) has been widely applied in various fields.
FIG. 1 is a cross-sectional diagram of a light emitting diode 100 packaged by conventional wire bonding technique. The light emitting diode 100 includes a substrate 110, a N-type semiconductor layer 120, a light-emitting layer 130, a P-type semiconductor layer 125, and electrodes 140 and 145 contacted with the N-type semiconductor layer 120 and P-type semiconductor layer 125 respectively. The light emitting diode 100 is mounted on a packaged base 160, and the electrodes 140 and 145 of the light emitting diode 100 are electrically connected to conductive regions 150 and 155 of the packaged base 160 respectively.
Referring to FIG. 1, the light emitting diode 100 includes an illuminating region A (i.e. the region covering the light-emitting region 130) and a non-illuminating region B (i.e. the region not covering the light-emitting region 130). However, the electrode 145 screens out part of the light generated from the light-emitting region 130 in the illuminating region A, such that the intensity of the outputted light from the light emitting diode 100 will be reduced.
FIG. 2 is a cross-sectional diagram of a light emitting diode 200 packaged by known flip chip packaging. The light emitting diode 200 includes a transparent substrate 210, a N-type semiconductor layer 220, a light-emitting layer 230, a P-type semiconductor layer 225, and electrodes 240 and 245 being contacted with the N-type semiconductor layer 220 and P-type semiconductor layer 225 respectively. The light emitting diode 200 is connected to conductive regions 250 and 255 of the packaged base 260 by solder 270 without the need of die bonding process and/or wire bonding process.
Referring to FIG. 2, in the illuminating region A of the flip-chip light emitting diode 200, the light emitted upwardly will not be screened out by the electrode 245, such that the lighting efficiency of the flip-chip light emitting diode 200 would be better than that of the wire-bond light emitting diode 100. However, the flip-chip light emitting diode 200 still has a non-illuminating region B which typically occupies about 20 to 30 percents of the whole die size, and therefore has a limited light intensity.
Therefore, it is necessary to provide a structure and a manufacturing method for further improving luminous efficiency of the light emitting diode and method of the same.